Mainframes continue to play a critical role in large data centers around the world. Despite the rise of new technologies and the spread of more modern platforms, these systems—with more than six decades of history—remain highly relevant and essential for many organizations.

This article explores the key advantages of mainframes in terms of reliability, security and processing power, and explains how they can coexist with modern IT infrastructures.

It also looks at how advances in Artificial Intelligence (AI) and Machine Learning (ML) are reshaping migration and modernization tools, further enhancing the value of these legacy systems.

The main advantages of mainframe systems

Reliability and uptime

One of the main reasons mainframes are still widely used is their exceptional reliability. They are designed to deliver extremely high availability levels, often exceeding 99.999% uptime—commonly referred to as “five nines”—which corresponds to just 5.26 minutes of downtime per year.

The “z” in z/OS, one of the most widely used mainframe operating systems, stands for “zero,” symbolizing zero downtime. This level of reliability is the result of decades of continuous innovation and deep technical expertise.

This is particularly important in industries where downtime can lead to significant financial losses. Sectors such as banking, finance and healthcare rely on mainframes to ensure operational continuity and data security, highlighting how critical their resilience remains.

Processing power

Mainframes are designed to handle massive volumes of data and transactions. Their ability to process up to one trillion transactions per day makes them a cornerstone for large organizations that require significant computing power.

In many cases, a single mainframe can replace hundreds or even thousands of servers, simplifying infrastructure management and reducing operational costs. This level of performance is essential for companies that need to process large amounts of data in real time.

Security

With built-in encryption, advanced access controls and strict compliance with regulatory standards, mainframes provide a highly secure environment for managing sensitive data. This makes them particularly suitable for organizations operating in regulated sectors or handling critical information, such as financial institutions and government agencies.

According to a 2024 survey by Kyndryl and Coleman Parkes Research involving 500 companies worldwide, 68% of organizations consider security the most valuable feature of mainframes, followed by reliability (60%) and performance (55%).

This is also why 85% of companies that have begun modernizing their mainframe environments have chosen to retain them, rather than replace or fully migrate away from the platform.

Integration with cloud, APIs and DevOps

While mainframes are long-established systems, they have evolved to integrate effectively with modern technologies. Hybrid architectures allow organizations to combine the reliability and security of mainframes with the flexibility and scalability of the cloud, optimizing overall costs.

The adoption of APIs and microservices has further enabled seamless integration between mainframes and modern applications. Organizations can expose mainframe functionalities as APIs, allowing new applications to interact easily with existing systems. This approach supports innovation while preserving the value of legacy assets.

Another important aspect of modernization is the adoption of technologies such as Docker and Kubernetes, which enable containerized applications to run directly on mainframes. This simplifies the management of mixed workloads and allows mainframes to be integrated into DevOps pipelines, supporting more efficient scaling.

Integrating DevOps practices into mainframe environments also helps automate and standardize IT processes, improving efficiency and reducing operational risk.

AI, Machine Learning and GenAI: new tools for modernization

Artificial intelligence and machine learning are reshaping the IT landscape, and mainframes are increasingly incorporating these technologies to improve efficiency and accelerate modernization. Advanced tools, such as Machine Learning for z/OS, can analyze code dependencies, optimize migration timelines and integrate with CI/CD pipelines, artifact repositories and Git environments. Generative AI (GenAI) is also being used to automate tasks such as documentation generation and infrastructure-as-code (IaC) scripting, simplifying the management of cloud environments.

According to Kyndryl, 86% of organizations are already implementing AI on mainframes. Recent studies also report efficiency gains of up to 15% and significant reductions in operational costs.

Why modernize mainframe systems?

According to Gartner, by 2027 organizations that fail to adopt appropriate tools for mainframe migration and modernization will face significantly higher costs than those that do.

The Kyndryl 2024 State of Mainframe Modernization Research Report also highlights clear economic and operational benefits: an average increase in profitability of 9%—rising to 11% when integrated with the cloud—and savings of up to $26.6 million per year.

These figures confirm that, despite being perceived by some as outdated, mainframes remain essential for 90% of the organizations that rely on them, both for their reliability and security and for their strategic role in business operations.

RES Suite and its role in mainframe modernization

RES Suite is one of the key assets supporting mainframe modernization and is included in Gartner’s Market Guide for tools supporting legacy and mainframe migration and modernization.

Its modular and highly customizable solutions help automate and simplify the documentation of software assets, improving efficiency and reducing update times.

RES Suite supports organizations throughout the entire modernization journey, from initial discovery of IT assets to full application transformation. This approach helps reduce technical debt and optimize workloads while maintaining high levels of operational reliability.

Gartner highlights the importance of adopting tools like RES Suite for organizations aiming to remain competitive over time.

Conclusion

Mainframes are far from being obsolete technologies. They continue to play a central role in modern data centers thanks to their reliability, security and processing power.

Their ability to integrate with technologies such as hybrid cloud, APIs, microservices and containerization makes them a solid foundation for many organizations.

As business needs evolve, mainframes continue to demonstrate their relevance, providing a stable and secure infrastructure for large-scale operations.

Looking to modernize your legacy systems? Get in touch for a consultation.